Apparatus for supporting a blast furnace

ABSTRACT

The present invention relates to an apparatus for supporting the furnace body of a blast furnace. Said apparatus is characterized by supporting the furnace body near the middle part of its shaft above the center of gravity of the furnace body; more in detail, it is so constructed as to support the furnace body with a supporting member provided around the shell of the shaft above the center of gravity of the furnace body so as to support the refractory lining of the furnace body, with a plurality of struts set on the foundation so as to support said supporting member, and with a plurality of supporting stands adjustable in height each placed between each of said struts and said supporting member, and also as to support the top unit of the furnace with a plurality of columns supported by said struts.

United States Patent Ueshima et al.

[ 51 Oct. 31, 1972 [541 APPARATUS FOR SUPPORTING A BLAST FURNACE [73] Assignee: Nippon Steel Corporation, Tokyo,

Japan 221 Filed: Feb. 24, 1971 21 Appl.No.: 118,349

Related U.S. Application Data [63] Continuation-impart of Ser. No. 662,337, Aug.

22, 1967, abandoned.

[52] US. Cl ..266/25, 266/43 [51] Int. Cl. ..C2lb 7/00 [58] Field of Search ..266/25, 32, 43

[56] References Cited UNITED STATES PATENTS 2,101,391 12/1937 Grotewohl ..266/25 3,371,918 3/1968 Ueshima et al ..266/43 3,431,691 3/1969 Greaves et a1 ......266/25 FOREIGN PATENTS OR APPLICATIONS 809,590 2/1959 Great Britain ..266/25 884,052 12/1961 Great Britain ..266/25 Primary Examiner-Gerald A. Dost Attorney-Wenderoth, Lind & Ponack [57] ABSTRACT The present invention relates to an apparatus for supporting the furnace body of a blast furnace. Said apparatus is characterized by supporting the furnace body near the middle part of its shaft above the center of gravity of the furnace body; more in detail, it is so constructed as to support the furnace body with a supporting member provided around the shell of the shaft above the center of gravity of the furnace body so as to support the refractory lining of the furnace body, with a plurality of struts set on the foundation so as to support said supporting member, and with a plurality of supporting stands adjustable in height each placed between each of said struts and said supporting member, and also as to support the top unit of the furnace with a plurality of columns supported by said struts.

5 Claims, 7 Drawing Figures P'A'TE'N'TEUncIQI m2 3.701.516

SHEEY 1 OF 3 FIG. I PRIOR ART FIG. 2 FIG. 3 PRIOR ART INVENTORS Kumoo Ueshimu Kenzo Fukudo Mosokuzu Yoshinugc Hiroshi Nukozono wm, W

SHEET 2 OF 3 PATENTEDncm I972 KUMAO UESHIMA, KENZO FUKADA, MASAKAZU YOSHINAGA and HIROSHI NAKAZONO,

Inventors,

y 26:1 'Attvorneys P'A'TENTED B I972 3.701.516

' sum 3 OF 3 V KUMAO UESHIMA,

\ KENZO FUKADA,

v MASAKAZU YOSHINAGA &

HIROSHI NAKAZONO,

INVENTORS BY up ATTORNEYS APPARATUS FOR SUPPORTING A BLAST FURNACE This application is a Continuation-in-Part of Ser. No. 662,337, filed Aug. 22, 1967 and now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention The'present invention relates to an apparatus for supporting the furnace body of a blast furnace, accessaries or units on and around the furnace body; which apparatus is characterized by supporting such supported items above the center of gravity of the furnace body.

2. Description of the Prior Art A blast furnace of conventional type is mainly composed of the furnace body, the top units provided around the upper part of the furnace body and a unit provided around the lower part of the furnace body. Said furnace body consists of the hearth, tuyere, bosh, belly, shaft and throat; and its inside is lined with a refractory material. Because the vertical dimension is unbalancedly greater than the horizontal dimension, and because the weight of all the abovementioned items is put on the furnace body, there is needed such a supporting structure to settle the furnace body firmly.

In the blast furnace of conventional type, the upper part of the shell of the bosh is supported with plate provided at the lower end of the shell of the shaft, and said plate is supported with 7 to 9 struts. The top unit of the furnace is supported with 4 to 6 columns distributed to said struts, or with columns provided independently from said struts.

The prior art supporting structure has several disadvantages. The point of support is positioned below the center of gravity of the blast furnace so that the furnace has poor resistance to horizontal loads. The refractory lining in the furnace is worn away during operation, and the wear is greatest in the vicinity of the support point. Consequently the strength of the furnace body at the point of support is greatly reduced, resulting in low structural stability of the furnace.

A weight of several thousand tons of the furnace body rests on its shell, which is supported by the supporting member; therefore, a great load is put on the junction between the shell and the supporting member and also on the supporting member itself. In order to reinforce said junction and the supporting member, there are needed a complicate structure and a great number of members therefor. According to blowing in and other operation conditions, there take place changes of temperature of the furnace body, causing a movement of the supporting point of the supporting member along the directions of axis and radius. Such movement spoils uniformity in the support of the load of the furnace body by the supporting member. However, supporting apparatuses of conventional type have no such device as to simplify adjustment of the position of the supporting point which is changeable due to thermal deformation of the furnace body.

SUMMARY OF THE INVENTION The present invention overcomes these disadvantages. By supporting the furnace at a point above the center of gravity, the furnace is made stable with respect to horizontal loads resulting from earthquakes and the alike. Also, by positioning the support apparatus at a point above the center of gravity, the instability caused by supporting the furnace at a point which is greatly weakened by the physical wear of the descending charge and the chemical erosion resulting from the reduction and melting of the iron ore is avoided. Most of the wear and erosion occurs in the lower portion of the shaft; very little occurs in the middle portion of the shaft.

According to the present invention, the furnace body is supported by means of an annular supporting member fixed on the shell of the furnace body and the supporting stands adjustable in height, simplifying the structure of the supporting apparatus and making it possible to distribute the load of the furnace body uniformly to struts.

Thus, an apparatus of the present invention for supporting the furnace body of a blast furnace, consists of a plurality of struts provided upright on a foundation, shell so formed as to the refractory lining of the furnace body, a supporting member made of a plurality of annular plates and reinforcement plates fixed on the outside of said shell near the middle part of the shaft above the center of gravity of the furnace body, a plurality of supporting stands adjustable in height, provided on the upper surface of girders placed over said struts so as to bridge each two of them for setting said supporting member, and a plurality of columns mounted upright on the top of said struts for supporting the top unit of the furnace body.

An object of the present invention is to provide an apparatus for supporting the furnace body of a blast furnace so as to enhance durability and stability of the furnace.

Another object of the present invention is to provide an apparatus for supporting the furnace body of a blast furnace constructed into a simple structure and so as to distribute the load of the furnace body uniformly over I the supporting member.

BRIEF DESCRIPTION OF THE DRAWINGS The following is a brief explanation of drawings.

FIGS. 1 and 2 show a vertical section view of a blast furnace provided with a furnace body supporting apparatus of conventional type.

FIG. 3 shows a vertical section view of a blast furnace provided with a furnace body supporting apparatus of the present invention.

FIG. 4 shows an enlargement of the vertical section of a part around the support of the blast furnace of FIG. 3.

FIG. 5 shows the sectional view along the line VV of the part of FIG. 4.

FIGS. 6 and 7 show respectively an enlarged front view and a side view of a supporting stand of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT As illustrated in FIGS. 1 and 2, blast furnaces known in the prior art comprise a furnace body 1, equipment at the top of the furnace body including a charging device 2 and a gas collection pipe 3, and equipment which surrounds the lower part of the furnace. Said equipment includes a bustle pipe 4, etc. The furnace body comprises a hearth 5, atuyere 6, a bosh 7, a belly 8, a shaft 9 and a throat 10. Each of said sections contains a refractory lining 11. The furnace body is filled with solid and molten materials such as iron ore and coke. The refractory lining 11 is surrounded by a shell 12 and cooled by means of cooling plate 13 inserted therein.

The furnace body and the devices surrounding the furnace body require a supporting apparatus which has good stability. In the supporting apparatus as known in the priorart and shown in FIG. 1, the refractory lining 11, charge 16, shell 12, etc. located above the bosh 7, are normally supported by having "ring plates 14 which are located at the bottom of the shell 12 surrounding the shaft 9, resting on from 7, to 9 struts. On the other hand, the charging device 2, the gas collection pipe 3, etc. located at thetop of the furnace are normally supported by from 4 to 6 columns 17 provided separately, from the struts 15. FIG. 2 shows another conventional supporting apparatus. In said apparatus, columns 18 which provide a means for supporting the equipment at the top are positioned vertically on the shaft bearing struts 15. The refractory lining 11, charge 16, shell 12, etc. locatedbelow the tuyere 6 are directlysupported by a foundation 19, so that it is not necessary to provide them with any other means of support. I

Said supporting apparatus is known to the prior art, have several disadvantages. The point of support 14 is positioned below the center of gravity 20 of the blast furnace; therefore, the furnace has poor resistance to horizontal loads resulting from earthquakes and the like. The refractory lining contained within the furnace body is subjected to'physicalwear when the charge descends into the furnace, and to chemical erosion in the course of the reduction and melting of the iron ore.

Said wear and erosion is represented by the dotted line 21 in FIG. 1. It is greatest in the vicinity of the ring plate 14, that is, near the point where the upper portion of the furnace is supported. Consequently, the strength of the furnace body at the point of support 14 is greatly reduced, resulting in a low structural stability of the blast furnace.

' In the system of supporting a furnace -:body 1 with struts through a supporting member fixed around the shell 12 of said furnace body 1,- putting a greater part of the load of said furnace body 1 (including its content 16) on said shell 12, a great load is put on the junction between the shell 12 and the supporting member and the supporting member itself. Therefore, according to a furnace body supporting apparatus of conventional type, the structure of such junction and that of the supporting members are complicate, requiring quantities of materials. Besides, according to blowing in and other operation conditions, the temperature of the furnace body tends to change, causing a movement of the position of the supporting point of the supporting member in the directions of axis and radius. Especially a vertical movement spoils uniformity in the support of'the load of the furnace body 1 by the supporting member. This may cause dsviation of load and the resulting production of excessive stress over said supporting member. Therefore, it is necessary to adjust the positionof the supporting point of the supporting member to offset a movement of said point for supporting the furnace body 1, thereby maintaining the furnace body 1 in the normal state. However, supporting apparatuses of conparatus, high durability and stability of which are ensured by supporting the furnace body by means of an annular supporting member fixed on the outside of the shell of said furnace body near the middle part of the shaft above the center of gravity of said furnace body and also by supporting stands adjustable in height.

Referring to FIG. 3, the supporting apparatus of the present invention is characterized in that the furnace body, charge, etc., located above the belly, are supported by having a support member 25, positioned around the shaft 9 and near the middle 22 of the length of the shaft, rest on the struts 23 which are fixed on the foundation 19. The equipment at the top of the furnace is supported by columns 24 mounted on the struts 23 and extending vertically therefrom. The shaft is supported at a point 22 which is always above the center of gravity 20 of the furnace, and which is near the middle of said shaft 9.

1n the apparatus of the present invention, the supporting member 25 is fixedly welded on the outside of the nearly middle part of the shell 12 of the shaft 9. At this place, the shell 12 has several projections on the inside surface as brick supports 12a, which support several blocks of refractory lining 11; and the shell, as a whole, holds the furnace body 1. Inside a part of 12c of said shell 12 where the supporting member 25 is set, there is fixed a reinforcement plate 12b. Moreover, said part of the shell 12 has a greater thickness than of the shell 12. The reason of using two annual plates is 1 to make lighter by distribution the load of the furnace body put on the junction between the part 120 of the shell 12 and respective annular plates 26 and 27. According to a size or a weight of the furnace body, three or'more annular plates may be used. Between said annular plates 26 and 27 there is a reinforcement plate 28 inserted vertically and welded fixedly on the part 120 of the shell 12 and the annular plates 26 and 27,. Moreover, reinforcement plates 29 and 30 are fixed respectively on the uppersurface of the annular plate 26 and the lower surface of the annular plate 27. These annular plates 26 and 27 and the reinforcement 28, 29 and 30 go together to stand the load of the furnace body 1. According to a size or a weight of the furnace body 1, such reinforcement plates as 28, 29 and 30 may be omitted. As mentioned above, the ring girder structure of the supporting member 25 has such advantages that the width of a member fixed on the furnace body,

that is, the width of the annular plate, can be narrowed, thereby reducing bending stress put on said member, and that the furnace body 1 can be supported at a great number of supporting points around it.

On the other hand, there are mounted on a foundation 19 a plurality of struts 23 with their legs widely open. On the top of said struts 23 is mounted columns 24 along the line extending vertically therefrom. The number of struts 23 and columns 24 is free for choice, but the most appropriate number is four to six for each kind, generally the same number as the other kind, for supporting the blast furnace from around. Girders 31 bridge between said struts 23. On the upper surface of said girders 31, one annular plate 32 is fixed,'encircling said furnace body 1. Between this annular plate 32 and the annular plate 27 of said supporting member there are provided a plurality of supporting stands 33, I6 stands in the embodiment of the present invention, through these supporting stands 33 and said annular plate 32, the load of the furnace body 1 is transmitted from said supporting member 25. Such supporting stands 33 may be provided on the girder 31 directly but i not through the annular plate 32.

As shown in FIGS. 6 and 7, said supporting stand 33 consists of a base 34 fixed by welding or otherwise on said annular plate 32, a medium block 39 fixed on the upper surface of said base 34, and another medium block 41 fixedon the bottom surface of the annular plate 27. Said base 34 is so constructed as to form a frame, together with vertical members 35 and 36 and a horizontal member 37, all being shaped like plate. The lower medium block 39 has two grooves 40 on the upper surface. Also is the upper medium block 41. The bottom surface of the grove 42 of said medium block 41 is slant in the long direction, to correspond with the inclination of the upper surface of a wedge-shaped cotter 43. Said medium blocks 39 and 41 are so provided as to have their respective grooves 40 and 42 face each other.

ln relation to the abovementioned arrangement of the medium blocks 39 and 41, the so facing grooves 40 and 42 have a cotter 43 inserted with its upper surface slanting in the long direction. The width of said cotter 43 is made somewhat narrower than the inside width of the upper surface of the medium block 39 and the medium block 41.

Thus, the supporting member 25 is set on the girder 31 atop the strut 23 through the annular plate 32 and the supporting stand 33. The supporting member 25 is connected to the supporting stand 33 with a bolt 46 running through a bolt hole 47 made on the annular plate 27 and a bolt hole 38 made on a horizontal member 37 of the supporting stand 33. The setting of said bolt 46 is loose, and there is provided a gap of considerable dimension so that the supporting member can move against the supporting stand 33 in the horizontal or vertical direction. Therefore, deformation of the furnace body 1 is not hindered by the strut 23, the supporting member 25, the girder 31, the supporting stand 33 or others; so the production of excessive stress, which may be caused to such members by restricting deformation of the furnace body 1. Furthermore, even if the furnace body 1 is deformed in the vertical direction, there will be no problem at all, as the height of the supporting stand 33 can be adjusted by pushing deeply or pulling out the cotter 43 of the supporting stand 33, making it possible to continue holding horizontal the annular plate of the supporting member 25, and distribute the load of the furnace body 1 uniformly to the struts 23.

Moreover, as the columns 24 are set directly atop the struts 23, the load of the units around the top'of the furnace body 1 supported by said columns 24 is not put directly on the furnace body 1.

Because of the abovementioned structure of the apparatus of the present invention, a gas ascension pipe 3, the shaft 9, the belly 8, etc., together with the refractory lining 11, a cooling plate 13 and the content of the furnace 16, are firmly supported by the struts 23 through the supporting member 25.

The advantages of this invention are as follows. Since the erosion and wear of the refractory lining of the furnace body scarcely take place at the middle part of shaft, the furnace body supported at the middle part is free from the aforesaid defect of the prior apparatus and therefore may be a stable and durable structure. Beside, since the furnace is supported above the center of gravity thereof, the furnace may be stable with respect to horizontal loads due to earthquake and the like. Also, as the supporting member is of ring girder structure, there is needed no complicate construction of the junction with the shell, even though said supporting member holds the load of the whole of the furnace body, not quantities of materials. Said supporting member is set on the supporting stand which can be easily adjusted according to a movement of the supporting point of said supporting member, making it possible to maintain uniformity in the distribution of the load of the furnace body to the struts.

What is claimed is:

1. An apparatus for supporting the furnace body of a blast furnace, which comprises a plurality of struts mounted upright on a foundation, an shell formed so as to support the refractory lining of the furnace body, a supporting member consisting of a plurality annular plates and a plurality of reinforcement plates fixed on the outside of a shaft in its middle part above the center of gravity of the furnace body, a plurality of supporting stands for setting said supporting member, such stands being adjustable in height and provided on girders, each girder bridging between each two of said struts. and a plurality of columns mounted upright atop said struts for supporting units around the top of the furnace body.

2. The apparatus for supporting the furnace body as claimed in claim 1, wherein a part of the shell of the furnace body for fixing the supporting member, is made thicker than the other parts.

3. The apparatus for supporting the furnace body as claimed in claim 1, wherein a plurality of vertical reinforcement plates are provided between an upper and a lower annular plates of the supporting member, and

5. The apparatus for supporting the furnace body as claimed in claim 1, wherein two medium blocks facing each other are provided on the supporting stand, and a wedge-like cotter is inserted between said two medium blocks.

ii l 

1. An apparatus for supporting the furnace body of a blast furnace, which comprises a plurality of struts mounted upright on a foundation, an shell formed so as to support the refractory lining of the furnace body, a supporting member consisting of a plurality annular plates and a plurality of reinforcement plates fixed on the outside of a shaft in its middle part above the center of gravity of the furnace body, a plurality of supporting stands for setting said supporting member, such stands being adjustable in height and provided on girders, each girder bridging between each two of said struts, and a plurality of columns mounted upright atop said struts for supporting units around the top of the furnace body.
 2. The apparatus for supporting the furnace body as claimed in claim 1, wherein a part of the shell of the furnace body for fixing the supporting member, is made thicker than the other parts.
 3. The apparatus for supporting the furnace body as claimed in claim 1, wherein a plurality of vertical reinforcement plates are provided between an upper and a lower annular plates of the supporting member, and said reinforcement plates are welded with the outside of the shell and the bottom and the upper surfaces respectively of the upper and lower annular plates.
 4. The apparatus for supporting the furnace body as claimed in claim 1, wherein supporting stands are fixed on annular plate fixed on girders.
 5. The apparatus for supporting the furnace body as claimed in claim 1, wherein two medium blocks facing each other are provided on the supporting stand, and a wedge-like cotter is inserted between said two medium blocks. 